Regulating belt tension in tangential-belt drive arrangement for the whorls of a yarn-twisting machine

ABSTRACT

A drive motor of a tangential drive for the whorls of a yarntwisting machine, and its drive pulley are carried on a slider on a fixed support. A pair of threadedly interengaged elements are braced between the slider and the support such that on rotation of one of the elements relative to the other the slider is displaced relative to the support and belt tension is adjusted. A piston-and-cylinder arrangement as a fluid-pressure measuring device or detector is provided between the elements and the slider to sense the pressure they exert against the slider. A switch is connected to this piston and cylinder and operates when pressure therein drops below a predetermined level corresponding to a minimum belt tension. This switch produces an output which is employed to readjust the belt tension. A motor may be coupled to one of the threaded elements and to the switch to operate this motor and readjust tension automatically.

United States Patent 1191 Greive et al. Nov. 6, 1973 [54] REGULATING BELT TENSION IN 2,279,537 4/1942 Tillinghast 57/105 TANGENTIAL BELT DRIVE 2,176,839 10/1939 Gordon ARRANGEMENT FOR THE WHORLS OF A 1,860,955 5/1932 Rowe 57/105 YARNTWKSTING MACHINE Primary Examiner-Donald E. Watkins [75] Inventors: Aloys Greive, Munster/Westf.; Atmmey |(ar| F. Ross Theodor Tiemann, Bosensell/Munster, both of Germany ABSTRACT [73] Asslgnee: Hamel Zwmmaschmen A drive motor of a tangential drive for the whorls of a Munster/westf" Germany yarn-twisting machine, and its drive pulley are carried [22] Filed: Mar. 1, 1972 on a slider on a fixed support. A pair of threadedly interen a ed elements are braced between the slider and [2]] Appl' 230682 the su psort such that on rotation 0'11" one of the elements relative to the other the slider is displaced relative to [30] Foreign Application Priority Data the support and belt tension is adjusted. A piston-and- Mar. 2, 1971 Germany P 21 09 888.4 cylinder arrangement as a fluid-Pressure measuring vice or detector is provided between the elements and 52 us. 01 57/105, 74/242.11 0, 57/156 the Slider Sense the P they exert against the 51 1m. (:1 Fl6h 7/10, DOlh 13/20 slid A Swhch is connected this Pism" and cylinder 58 Field of Search 57/1 R, 34 R, 92, and Operates when Pressure thereih drops below a P 57/104, 105, 156; 74/2421, 24211 C determined level corresponding to a minimum belt ten- V sion. This switch produces an output which is employed [561 1 References Cited to readjust the belt tension. A motor may be coupled UNITED STATES PATENTS toone of the threaded elements and to the switch to operate this motor and readjust tension automatically. 3,638,781 2/1972 Comley 74/242.1lC X 2,689,448 9/1954 Winslow et al. 57/105 10 Claims, 5 Drawing Figures Patented Nov. 6, 1973 3,769,786

2 Sheets-Sheet l 76 7 a I I 1' [6 I l F 85 0 83 6 54 54 5 FIG./

Tv/a I I a REGULATING BELT TENSION IN TANGENTIAL-BELT DRIVE ARRANGEMENT FOR THE WHORLS OF A YARN-TWISTING MACHINE CROSS-REFERENCE TO RELATED APPLICATION This application relates to commonly assigned application Ser. No. 34,007 filed 4 May 1970.

FIELD OF THE INVENTION The present invention relates to an apparatus for regulating the tension in a belt of a tangential-belt-drive arrangement for driving one or more rows of whorls in a yarn-twisting machine. More specifically this invention concerns a method of and and apparatus for ad justing the tension in such a drive arrangement used in thread or yarn spinning and twisting installations.

BACKGROUND OF THE INVENTION In the spinning and twisting of yarn a drive arrangement has been found to be useful wherein a very long flat belt tangentially engages the whorls of a plurality of bobbin-carrying spindles. Such engagement allows high rotation speeds to be obtained with a minimum of complication. The amount of torque that such an arrangement can'transmit to the spindles is admittedly slight, however it is sufficient for the spinning and twisting of yarn, and enables the operators to take off full or empty bobbins by hand without the necessity of stopping the whole set of spindles or providing a complicated decoupling arrangement on each spindle.

The tension of the belt in such arrangements is of extreme importance. If the belt loosens, the inertia or friction at each whorl will greatly decrease energy transmission to the spindles, thereby making these spindles rotate at a reduced rate so that the spinning or twisting will take place nonuniformly. This problem is aggravated by the great length of the belt, since the capacity of stretch in a belt is directly proportional to its length.

Many solutions have been attempted to maintain a uniform tension in the belt at all times. These solutions have been characterized by complicated mechanisms which themselves often create more "problems than they solve.

OBJECTS OF THE INVENTION It is therefore an object to provide an improved method of regulating the tension in the belt of a tangential-beltdrive arrangement for the whorls of a yarntwisting machine.

Another object is to provide improved apparatus for regulating the belt tension in such an arrangement.

A further object is to provide an apparatus which is relatively simple and which accurately maintains the tension in such a belt-drive arrangement above a certain minimum.

SUMMARY OF THE INVENTION tween the slider and the support such that relative rotation of these elements in one sense will displace the slider and increase belt tension. To one side of the sensitive device (responsive to fluid pressure) which is coupled to a switch such that when the force exerted by the elements against the slider drops below a predetermined level corresponding to minimum belt tension the switch is actuated. Means is provided to rotate one of the elements to regulate this tension when the switch is actuated. Such means can be a simple motor connected by a gear to one of the threaded elements and operated directly by the pressure switch. Thus the force between the elements and the slider is sensed, is compared with a reference value in the switch, and an input signal is produced to take corrective action to restore a predetermined control point.

DESCRIPTION OF THE DRAWING The above and other objects, features, and advantages will become apparent from the following description, reference being made to the accompanying draw threaded elements there is provided a pressureing in which:

FIG. 1 is a side view, partly in section, showing a first embodiment of the present invention;

FIGS. 2 and 3 are views similar to FIG. 1 showing two further embodiments of the present invention;

FIG. 4 is a top view of the embodiment of FIG. 3; and

FIG. 5 is a diagrammatic view of the control circuit of FIGS. 3 and 4. l

SPECIFIC DESCRIPTION As seen in FIG. 1 a drivearrangement has a pair of uprights 10 and 10 between which a pair of horizontal beams 12 and 12' extend. A pair of parallel and horizntal tie rods 14 and 14 are carried in seats 16 on the two uprights 10 and 10' and a slider 18 is displaceable along these rods 16 and 16'. The slider 18 carries an electric drive motor 20 having a vertical output shaft 22 on which a drive pulley 24 is mounted. A flat drive belt 26 is spanned over this pulley and engages the whorls of spindles 84 with the help of idler pulleys or wheels 83 that urge this belt 26 into tangential contact with these whorls 85. Empty cores are fitted over these spindles 84 for twisting yarn.

A forklike support 28 rotatably supports an internally threaded nut 31 on the support 10. This nut 31 is pro vided with a bevel gear 30 embraced by the support 28. A threaded spindle 32 is received in thenut 31 and has an unthreaded end portion 34 formed with an axial slot into which fits a key 40 on a bore 36 in an extension 38 of the slider 18. The end of the unthreaded portion bears on a piston-cylinder arrangement 42 constituted by a piston 44 formed on the spindle 32, and a cylinder 46 provided on the slider 18 together forming a chamber filled with hydraulic fluid. A diaphragm can beprovided in place of the piston 44.

A conduit 48 connects the chamber 46 with a pressure-sensitive switch 50 comprising a wiper 54 pivotal through a 270 arc and engageable at the arc extremeties with adjustably displaceable sectors 52 and 52' connected to a normally open latching relay 55 in turn connected through wires 56 to a drive motor 58 carrying a bevelgear 60 meshing with the gear 30.

The device functions as follows:

Assuming the tension in belt 26 to be correct the wiper 54 will lie between the sectors 52 and 52' and the motor 58'will not operate. Themotor 20 will turn and drive the two rows of spindles 84.

As the tension inevitably dropsoiff, due to the considerable length of belt needed to drive many spindles, the

wiper 54 will move back, counterclockwise, until it engages the sector 52. This will close and latch the relay 55 and cause the motor 58 to operate and screw the sleeve 31 around the threaded spindle 32, thereby moving the slider 18 to the right as seen in FIG. 1. Such movement will increase belt tension, thereby moving the wiper 54 clockwise until it engages the sector 52. Once this sector is engaged the relay 55 is unlatched and the motor 58 is stopped. The provision of the second sector 52' eliminates hunting of the circuit. The outer sector contact 52 may be on disk with respect to which the inner sector contact 52 is angularly adjustable to vary the spacing between contacts 52 and 52 (and 152 and 152').

Clearly adjustment of the tension in belt 26 will follow automatically whenever it drops below a predetermined level, that pressure necessary to keep the wiper 54 out of the sector 52.

Reference numerals of FIG. 1 are increased by 100 and used wherever applicable in FIG. 2, where similar structure is shown.

The main difference in FIG. 2 is that a pair of sliders, 118 and 62 are shown. The slider 118 supports the drive motor 120 whose shaft 122 carries a two-belt pulley 74. The slider 62 serves as mount for a vertical shaft 64 carrying a two-part pulley 66 whose upper region 68 is looped by the belt 126 and whose lower part 70 is connected via two V-belts 72 to the pulley 74. A spindle 76 is threaded into the slider 62 at 80 and is connected axially to the slider 118 at 78. This spindle 76 is provided with a handwheel 82 that allows the user to adjust tension in the belts 72 by separating the carriages 62 and 116. Both sliders 116 and 62 are displaced by the spindle 132 as in the FIG. 1 embodiment. Members 52 and 152 constitute circuit-closing contacts while members 52', 152' are circuit-opening con tacts.

In FIGS; 3-5 structure identical to that of FIG. 1 is shown with its referencenumeral increased by 200.

In this embodiment the spindle 232 is provided on its unthreaded portion 234 with a handwheel 88 and this spindle has its threaded portion 92 threaded into the support 210 at 90. A bearing 86 is provided between spindle 234 and piston 244. Thus the support itself constitutes one of the adjustment elements.

' Furthermore the indicator 250 has a wiper 254 which is engageable with a pair of displaceable sectors 96 and 98, the latter being further counterclockwise than the the wiper 254 and one contact of a normally open relay 95 and its other side connected to one side of a signal horn and lamp 94 and to two relays 95 and 97. These relays are both shown in the actuated positions.

Under normal conditions the wiper 254 makes no contacts with any of the conductive sectors. When however the pressure in back of piston 244 drops the wiper will contact the sector 96 to actuate the hornlamp alarm 94 through leads 256. At this moment either an operator should come to adjust the wheel 88 or a motor 87 should turn it through a slip clutch 85.

If for some reason this adjustment is not carried out the wiper will move back on into the sector 98 where it will close the normally open relay 95 through leads 100, which in turn operates the normally closed heavyduty relay 97 that shuts off the supply of power from three-phase source 93 to motor 220. Actuation of the hand wheel to tighten the belt is all that is needed to return the drive to operation. The switches 89 can be used to cut out either of the sectors 96 or 98, if desired.

In all of these arrangements a minimum of working parts serves to keep a predetermined amount of tension in the belt which engages the whorls of the many bobbin-carrying spindles.

We claim:

1. An apparatus for regulating the tension in the belt of a tangential-belt-drive arrangement having a belt spanned over a drive pulley and tangentially engaging a plurality of bobbin spindles, said apparatus comprising:

a fixed support member;

a slidable member displaceable on said support member and rotatably carrying one of said pulleys whereby sliding of said slidable member in one direction increases the tension in said belt;

a first element carried on said fixed support member;

a second element threadedly engaging said first element and in force-transmitting relationship with said slidable member;

fluid-pressure-sensitive means between one of said elements and one of said members for producing a signal on force exerted by said elements against said slidable member dropping below a predetermined level representing a minimum belt tension; and

means for relatively rotating said elements for displacing said slidable member in said one direction upon production of said signal.

2. The apparatus defined in claim 1 wherein the rotating means is operatively connected to said pressuresensitive means. I

,3. The apparatus defined in claim 2 wherein said pressure-sensitive means includes a fluid-pressure sensor between said one element and said one member and a switch operatively connected thereto, said switch being connected to said rotating means.

4. The apparatus defined in claim 3 wherein said pressure sensor includes a cylinder body and a piston body, one of said bodies being mounted on said one element and the other body on said one member.

5. The apparatus defined in claim 3, further comprising signalling means connected to said switch for sensibly indicating the production of said signal.

6. The apparatus defined in claim 3, further comprising means connected to said pressure-sensitive means for arresting said drive pulley on said pressure dropping below a second predetermined level below said firstmentioned level.

7. A method of regulating the tension in a tangentialbelt-drive arrangement having a pulley carried on a slider displaceable relative to a support to adjust the belt tension by means of a pair of threadedly interengaged elements braced between the slider and the support, said method comprising the steps of:

sensing the pressure exerted by said elements against said slider and generating an output corresponding thereto; generating signal on said output dropping below a predetermined level corresponding'to a minimum belt tension; and rotating one of said elements relative to the other element on production of said signal to displace said slider and increase belt tension. 8. The method defined in claim 7 wherein said output is hydraulic.

9. The method defined in claim 8 wherein said signal is electrical.

10. The method defined in claim 9 wherein said element is rotated automatically on production of said signal. 

1. An apparatus for regulating the tension in the belt of a tangential-belt-drive arrangement having a belt spanned over a drive pulley and tangentially engaging a plurality of bobbin spindles, said apparatus comprisinG: a fixed support member; a slidable member displaceable on said support member and rotatably carrying one of said pulleys whereby sliding of said slidable member in one direction increases the tension in said belt; a first element carried on said fixed support member; a second element threadedly engaging said first element and in force-transmitting relationship with said slidable member; fluid-pressure-sensitive means between one of said elements and one of said members for producing a signal on force exerted by said elements against said slidable member dropping below a predetermined level representing a minimum belt tension; and means for relatively rotating said elements for displacing said slidable member in said one direction upon production of said signal.
 2. The apparatus defined in claim 1 wherein the rotating means is operatively connected to said pressure-sensitive means.
 3. The apparatus defined in claim 2 wherein said pressure-sensitive means includes a fluid-pressure sensor between said one element and said one member and a switch operatively connected thereto, said switch being connected to said rotating means.
 4. The apparatus defined in claim 3 wherein said pressure sensor includes a cylinder body and a piston body, one of said bodies being mounted on said one element and the other body on said one member.
 5. The apparatus defined in claim 3, further comprising signalling means connected to said switch for sensibly indicating the production of said signal.
 6. The apparatus defined in claim 3, further comprising means connected to said pressure-sensitive means for arresting said drive pulley on said pressure dropping below a second predetermined level below said first-mentioned level.
 7. A method of regulating the tension in a tangential-belt-drive arrangement having a pulley carried on a slider displaceable relative to a support to adjust the belt tension by means of a pair of threadedly interengaged elements braced between the slider and the support, said method comprising the steps of: sensing the pressure exerted by said elements against said slider and generating an output corresponding thereto; generating signal on said output dropping below a predetermined level corresponding to a minimum belt tension; and rotating one of said elements relative to the other element on production of said signal to displace said slider and increase belt tension.
 8. The method defined in claim 7 wherein said output is hydraulic.
 9. The method defined in claim 8 wherein said signal is electrical.
 10. The method defined in claim 9 wherein said element is rotated automatically on production of said signal. 